Since an oxygen-base bleach has characteristic that it can be used for color-patterned materials, it has been the main stream of a bleach for clothes. On the other hand, the oxygen-base bleach is inferior in bleaching power in comparison with a chlorine-base bleach and thus, its improvement is required.
Many studies have been carried out for a bleaching activator utilizing an organic peracid, a bleaching activating catalyst containing a metal atom and the like for improving the bleaching power of the oxygen-base bleach.
It is well known that the bleaching activator is converted to an organic peracid by reacting with hydrogen peroxide and exhibits high bleaching power for stains and soils.
On the other hand, the method of utilizing a bleaching activating catalyst is reported in Nature, Vol. 369 (1994) pp 637-639, J. Am. Chem. Soc., Vol. 115 (1993) pp 1772-1773, which proposes the mechanism that a complex activates catalytically hydrogen peroxide in bleaching solution to impart high bleaching effect for stains and soils. Therefore, high bleaching power can be efficiently obtained by a small amount of a complex.
However, while these techniques afford high bleaching power, when the cleaning of clothes is repeatedly carried out or a composition is directly brought in contact with clothes in high concentration, problems are known that clothes are thinned and holed and that colored clothes are discolored.
It is considered that the damage and discoloration of clothes is caused by oxygen active species, which are generated by abnormal decomposition of hydrogen peroxide.
The damage and discoloration of clothes become remarkable when high concentrations of a bleach, a bleaching activator and a bleaching activating catalyst are brought in contact with clothes if a powder bleach remains on clothes without being adequately dissolved on dip-bleaching using a tub, a cleaning vessel and the like.
For the suppression of the damage and discoloration of clothes by a bleaching activator and a bleaching activating catalyst, there are proposed a suppression technique by intimately mixing a bleaching activator with mineral materials such as acid clay and bentonite in Japanese Unexamined Patent Publication No. Hei 6-057297, a suppression technique by a combination of a catalyst with radical trapping agents such as dibutylhydroxytoluene and mono-t-butylhydroquinone in Unexamined Patent Publication No. Hei 9-511774, a suppression technique by a combination of a catalyst with crystalline layered silicates in Japanese Unexamined Patent Publication No. Hei 9-137196, and a suppression technique by a combination of a catalyst with clay mineral in Japanese Unexamined Patent Publication No. Hei 9-025499.
However, these techniques have been inadequate for suppressing the damage of clothes without coloration while exhibiting high bleaching power. Namely, a suppression technique using a radical trapping agent is a technique of deactivating oxygen active species generated and suppressing the damage and discoloration. At the same time, however, the radical trapping agent reacted with oxygen active species disadvantageously colors and stains clothes. On the other hand, by a method of physically decreasing contact chance by granulating a bleaching activator or a bleaching activating catalyst with water-insoluble substances such as mineral materials, crystalline layered silicates and clay minerals and keeping distance from clothes, they are hardly soluble, solubility is not adequately secured and adequate bleaching effect is not occasionally exhibited. Further, while they were in adequately soluble and brought in contact with clothes for a long time, the bleaching activator and the bleaching activating catalyst were gradually dissolved and became highly concentrated near clothes, the damage and discoloration occurred occasionally and suppression effect was inadequate.
On the other hand, a detergent composition containing water-insoluble solid particles is proposed in Japanese Unexamined Patent Publication No. 2003-64574 for prevention of the deterioration of texture and a detergent containing cellulose as a disintegrating agent is proposed in International patent application published in Japan No. 2002-502456 and Japanese Unexamined Patent Publication No. 2000-192098.
However, a bleaching agent and a bleaching detergent having high bleaching power and further, suppressing the damage and coloration of clothes and the discoloration of dyes has been desired.